I pulled the brake booster out to clean it up. It had quite a bit of surface rust on it. Soaking it, face down in the safestrustremover.com stuff. Working very well taking the rustiness away.
You can see the light blue inspection mark on the "Delco Moraine" stamp in the 2:00 position on the face.
And on the top was a light blue mark that ran across from the front side to the back side at the 12:00 position, as well as an orange daub right at the top.
